Hydraulically operated pitch and tilt dozer



E. D. DUKE EI'AL HYDRAULICALLY OPERATED PITCH AND TILT DOZER 2 Sheets-Sheet l March 25, 1958 Filed April 15. 1955 2 v Sheets-Sheet 2 E. DQ DUKE ETAL HYDRAULICALLY OPERATED PITCH AND TILT DOZER Filed April 15. 1955 March 25, 1958 2,327,717 Patented Mar. 25, 1958 ice HYDRAULICALLY @PERATED PITCH AND THE DUZER Edward D. Duke, Chicago, and John R. Wilkinson, Mount Prospect, 111., assignors to International Harvester (Zornpany, a corporation of New Jersey Application April 15, 1955, Serial No. 501,529

7 Claims. (Cl. 37-144) This invention relates generally to bulldozers and more specifically to a bulldozer provided with hydraulic pitch and tilt means for the blade or moldboard thereof.

Many means are known in the art by which the blade or moldboard of the bulldozer may be adjusted to various angles of pitch and tilt. However, these pitch and tilt means generally require that the angles of pitch and tilt be varied through some mechanical adjustment at the moldboard and cannot be operated or controlled from the operators station on the bulldozer.

It is the object of the present invention to provide pitch and tilt means for a bulldozer which are simple in construction, eflicient in operation, and which may be operated to pitch or tilt the blade from the operators station on the tractor.

Other objects and features of the present invent on will be apparent upon a perusal of the following specification and drawings of which:

Figure 1 is a side elevational view of a bulldozer constructed according to the present invention;

Figure 2 is an enlarged fragmentary view of the structure shown in Figure 1;

Figure 3 is a partial cross-sectional view of the structure shown in Figure 2 and taken along the line 3-3;

Figure 4 is a rear view of the blade assembly removed from the push beams, the struts, the bracing links and the hydraulic rams extending from the tractor; and

Figure 5 is a rear view of the blade assembly in one position of tilt but removed from the struts and the hydraulic rams extending from the tractor and showing the push beams in cross section.

The present embodiment is the preferred embodiment but it is to be understood that changes can be made in the present embodiment by one skilled in the art without departing from the spirit and scope of the present invention.

For a detailed description of the present invention, reference is made to the drawings. The tractor is of the crawler type and comprises an operators station 11, an engine compartment 12, and a crawler track mechanism 13.

A pair of push beams 14 are provided and are each mounted at one end thereof to the track mechanism 13 through a pair of trunnions 15 positioned on each side of the tractor 10. The trunnions 15 permit pivoting of the push beams 14 about an axis transversely of the tractor 10 and further a limited amount of pivoting of the push beams 14 about their longitudinal axes.

A blade or moldboard 16 of any type well known in the art is also provided. The blade 16 comprises a curved plate 4%, a pair of side walls or wings 41 secured to plate 40, an upper bracing member 42 and a lower bracing member 43 secured to the rear surface of plate and to side walls 41, a plate 44 upstanding from upper bracing member 42, and a cutting edge removably secured to the lower longitudinal edge of plate 40. The lower rear side sections of the moldboard 16 are each provided with a flange 17 mounted thereto. The flanges 17 are each formed to have a lower U-shaped portion and an upper U- shaped portion with each of the portions being provided with a pair of openings axially aligned therethrough. The other or forward end of each push beam 14 is pivotally mounted between the lower U-shaped portion of one of the flanges 17 by means of pivotal mounting means 18.

A pair of double acting hydraulic rams 19 are also provided. The head end of each of the hydraulic rams 19 is pivotally mounted between the upper U-shaped portion of one of the brackets 17 by means of pivotal mounting means 20. A pair of struts 21 are also provided, and each of the struts 21 are pivotally mounted at one end thereof to a bracket 22 by means of pivotal mounting means 23. Each bracket 22 is secured to one of the push beams 14 intermediate the ends thereof. A pair of slide members 24 are also provided and are each formed to have a pair of projecting flange portions. The projecting flange portions of each of the slide members 24 are provided with a pair of axially aligned openings therethrough as can easily be seen in Figure 3. The other end of one of the struts 21, the rod end of one of the hydraulic rams 19, and the projecting flange portions of one of the slide members 24 are pivotally interconnected by a pin 25. The other ones of the struts 21, the hydraulic rams 19 and the slide members 24 are also connected in an identical manner. It can thus be seen that if the hydraulic ram 19 on the right side of the tractor 10, as shown in Figure 1, is contracted, the slide member 24 will be moved downwardly and forwardly of its position as shown in Figure 1. Further, if the hydraulic ram 19 is extended, the slide member 24 will be moved upwardly and rearwardly from its position as shown in Figure 1.

The upper rear side sections of the blade 16 are each provided with a channel member 26 which is secured thereto. Each of the channel members 26 are positioned directly above one of the flanges 17 with the channel of the channel member 26 positioned to lie in a vertical direction, as can readily be seen in the drawings. The slide members 24 and the channels of the channel members 26 are formed to have cooperating surfaces per mitting the slide members 24 to move upwardly and downwardly within the channels of the channel members 26, as the hydraulic rams 19 are extended and contracted. The length of stroke of the hydraulic rams 19, and the length of the struts 21 are such that the hydraulic rams 19 lie in a substantially vertical plane, and that the moldboard 16 is in a substantially upright position, with the hydraulic rams operated to some position between completely contracted and completely extended, as is substantially shown in Figures 1 and 4.

To properly brace the moldboard 16 relative to the push beams 14, a pair of bracing links 46 are provided. One end of each of the bracing links 46 is provided with a universal socket member 47. The socket members 47 are each mounted about a ball and pin member 48, and the ball and pin members 48 are mounted within a pair of brackets 49 which are secured to the lower bracing member 43 on the rear surface of the moldboard 16 in a spaced apart relationship to each other intermediate the ends of the moldboard 16. The other or rear ends of each of the bracing links 46 are mounted to the push beams 14 intermediate the ends thereof by a similar ar-' rangement and are designated generally with the numeral 51 in Figure 1.

To raise and lower the moldboard assembly a pair of hydraulic rams 3t? are provided. Only one hydraulic ram 30 is shown in Figure 1, however the other hydraulic ram 30 is disposed on the other side of the tractor 10 in the same position. The head end of each of the hydraulic rams 30 is pivotally mounted to the tractor 10 by means or" pivotal mounting means 31. The rod end of each of the hydraulic rams 30 is pivotally mounted to the rear p 3 v 7 face of the moldboard .16 through a bracket 32. As the hydraulic rams 30 are contracted the blade 16 is raised from the ground as the push beams '14 are pivoted about trunnions 15 in a counterclockwise direction, as. viewed. in Figure 1. As the hydraulic ra'ms 30 are-extended, an opposite pivoting taltes place to" lowerthe blade 16. if desired, any cable operated meanswell' known in the art. may be substituted forthe hydraulic rams 30 to raise and lower themoldboard. v i

Hydraulic conduits 34 and 35g are connected into the cylinder of the hydraulic'ram 19" on the left side of the tractor 10. Hydraulic conduits 36 and 37 are connected into the cylinder of the hydraulic ram 19 on the right side:

of the tractor 10. The hydraulic conduits 34, 35, 36 and 37' are connected to suitable hydraulic pump and valve means (notshown) on the tractor for selective operation of the hydraulic rams 19. Suitable hydraulic pump, valve and' conduit means (not shown) are also provided for the hydraulic rams 30 for proper operation thereof.

Turning next to a detailed description of the operation" of the instant invention in order that the cooperation be tween the various described elements may be ,more readily understood, reference is again made to the drawings. Discussing first a pitching of the moldboard 16, which may be described as a pivoting of the moldboard about a horizontal axis transversely of the tractor. In a pitching of the moldboard 16 both of the hydraulic rams 19 are simultaneously operated'in the same direction an identical amount. If the hydraulic rams 19'arefully extended,1the

slide members 24 will be moved in a circular'p'ath upwardly and rearwardly. The radii for the curves defined by thecircular motion of the slide members'24 are the struts 21 pivoting about pivotal mounting means 23. 'The upward component of travel of the slide members 24 will result in a sliding of the slide members 24 within the channels of the channel members 26, and the rearward travel of the slide members 24'will result in a pivoting of the moldboard 16 rearwardly about pivotal mounting means 18 resulting in the rearward pitch of the moldboard 16.

. Topi'tch the moldboard 16 forwardly, the hydraulic rams 19 are contracted. As the hydraulic rams 19 are contracted, the slide members 24 will be moved inla" circular ,path forwardly and downwardly from a posi ti'on' such as shown Figure 1. The radiifor' the circular path of the slide members 24 again are the struts 21. 1 The downward component of movement of theslide'mmbers 24' will result in a sliding of the members 24' within'the' channels of the channelmemb'ers 26 and the rem/are component of movement of the slide members 24-will result in a pivoting of the blade 16 in a clockwise (ur a: tion as viewed iii-Figure 1 about ivota-imounting means 18 to pitch the blade 16 forwardly. 7 p i In tilting of the moldboard 16, one of the hydraulic rams 19 is contra ctedwhile the other of the hydraulic ra'ms' 19 is extended. 1f the hydraulic rain 19 on the right'side of the tractor 10 is contracted by some amount and the hydraulic ram 19 on the left side of the tractor 10 isextended by some amount, the moldboard 16 will be tilted such that the left side of the moldboard is lowered and the right side of the moldboard is raised. In order that this operation may be more readily understood, referenceis made particularly to Figure 5. Assuming that the push beams 14 are removed from the trnnnions 15 and that the moldboard 16 is secured in a horizontal position; a contraction of the ram 19 on the right side of the tractor 10 will cause the slide member 24 associated therewith to'be moved downwardly within the channel member 26. Since the strut 21 associated therewith is of a fixed length greater than the distance between pivotal mounting means'23 and pivotal mounting means"18, the

downward movement of the slide'member 24 will cause a downward pivoting of the rear end of the'push beam 14 associated therewith about pivotal mounting, means 13. Conversely," whe'nthe hydraulic rat-n19 on the left side of the tractor 10 is extended the slide. member 24v willbe moved upwardly within channel member 26 and the strut 21 associated therewith will cause the push beam 14 connected thereto to be pivoted upwardly about pivotal mounting means 18. Thus with the moldboard 16 horizontally aligned the rear end of: the push beam 14 on the right side of the tractor 10 will be in some position below the height of the trunnions 15 from the ground and the rear end of the push beam, 14 on the left side of the tractor 10 will be in some position above the height of the trunnions 15 from the ground. To reconnect the rear ends of the push beams 14 to the trunnions- 15, it is then necesy to r s h ushbe m t Q th r shtside 9 the tractor 10 and to lower the push beam 14 on the left side of the tractor 10. This will result in a raising of the right side of the moldboard 16 and a lowering of the left side of the moldboard 16 to cause the moldboard 16 to assume one position 'of tilt- 'It should be noted that the push beams 14 are pivoted about their longitudinal axeswhen the moldboard is tilted. This rotation of the push beams:

14 about their longitudinal axes is provided for in the trunnions .15. Additionally, as the moldboard is pitched o'r tilted, the bracing links 46 will pivot about the described= universals to maintain a proper alignment with the push:

beams 14 and the moldboard 16. It should further be" noted that various combinations, of the operations pre: viously described may also be efiected Pitch and tiltm'aybe combined to various degrees, or only one hydraulic ram 19 may be operated in tilting, to cite a few examples;

Having described the invention, what is considered new and desired to be protected by Letters Patentis: 7

l. A bulldozer attachment for a tractor comprising: a pair of forwardly extending push beams pivotally mounted to said tractor, a moldboard-pivotally: mounted'tof-the forward ends. of said push beams, a pair of struts, each of said struts pivotally mounted at one end thereof to one of said push beams intermediate theends thereof? means connecting the other ends of each of said struts to said moldboard for sliding movement in a direction perpendicular to the axis of pivoting of said moldboard on said push beams, and means pivotally mounted between said moldboard and said other ends of said struts for pivoting saidstruts and for holding said struts in any pivoted position to positively secure said moldboard in any pivoted position. v

2; A bulldozer. attachment for a' tractor comprising: a pair offorwardly extending push beams pivotally mount ed to said tractor, a moldboard pivotally mounted to forward ends of said push beams, a pair of struts, each of said struts pivotally mounted at one end thereof to one 3. A bulldozer attachment for a tractor comprising: a

pair of forwardly extending push 'beam's' pivotally mounted to' said tractor, a moldboard pivotally mounted to the forward ends ofsai'd push beams, apair of struts; each of said struts pivotally mounted at oneend thereof to one of said push beamsfintermediate the ends thereon-a:

of channel members, each ,of s aid pairpof channel themb'ers mounted to said moldboard substantially vertically above one ofthe pivotal connections'of said moldboard t6 Pi of 'i'dru h beam it t e l. ts f h n el member directed perpendicular to the axis of pivotingpf saidpnioldb oard on said push beams, a pair of slide meinan;

berslshdably mounted within said channels t; nel memb ers, meanspivotally connecting the other endsj 0; ans: some an nare means. an tvotan mounted between said notations and said fitiir ends of said struts for pivoting said struts and for holding said struts at any pivoted point.

4. In a bulldozer attachment as defined in claim 3, said last mentioned means comprising a pair of double acting hydraulic rams.

5. A bulldozer attachment for a tractor comprising: a pair of truunions mounted on each side of said tractor, a pair of forwardly extendingpush beams each mounted at one end thereof on said trunnions for pivoting movement about an axis transversely of said tractor and for a limited amount of rotative movement about the longitudinal axes of said push beams, a moldboard, means pivotally mounting the forward ends of said push beams to the lower side sections of said moldboard, a pair of struts, each of said struts pivotally mounted at one end thereof to one of said push beams intermediate the ends thereof, means connecting the other ends of each of said struts to the upper side sections of said moldboard for sliding movement in vertical planes, each of said planes including one of said struts and one of said push beams, and means pivotally mounted between said moldboard and said other ends of said struts for pivoting said struts and for holding said struts in any pivoted position.

6. In a bulldozer attachment as defined in claim 5, said last mentioned means comprising a pair of double acting hydraulic rams, each of said hydraulic rams positioned substantially in a vertical direction in one of the planes including one of said struts and one of said push beams.

7. A bulldozer attachment for a tractor comprising: a pair of trunnions mounted on each side of said tractor, a pair of forwardly extending push beams mounted on said trunnions, a moldboard, a pair of brackets mounted on the rear surface of said moldboard substantially at the lower side sections thereof, means pivotally connecting the forward ends of said push beams to said brackets, 21 pair of channel members secured to the rear surface of said moldboard substantially at the upper side sections thereof, a pair of double acting hydraulic rams, means pivotally connecting the head ends of said hydraulic rams to said brackets, a pair of slide members slidably mounted within said channel members, a pair of struts, means pivotally mounting one end of each of said struts to one of said push beams intermediate the ends thereof, means pivotally interconnecting the other end of each of said struts, the rod end of each of said hydraulic rams, and

each of said slide members, said pair of hydraulic rams operable to move said slide members upwardly and downwardly within said channel members and to maintain said slide members in any upward and downward position, and means mountable between said moldboard and said tractor for raising and lowering said moldboard relative to the ground.

References Cited in the file of this patent UNITED STATES PATENTS 2,530,414 Wells Nov. 21, 1950 2,669,367 Wills et a1 Feb. 16, 1954 FOREIGN PATENTS 138,608 Australia Sept. 8, 1950 153,071 Australia Sept. 2, 1953 

